Emergency over as planet-hunting Kepler recovers

NASA has taken its Kepler Spacecraft out of ‘emergency mode’ (EM), ending the most fraught stage of the planet-seeker’s seven-year stretch in space.

Over the weekend, Kepler, one of NASA’s most successful space programmes ever, got into trouble, initiating EM – the most fuel-intensive mode it can reach.

It caught NASA engineers by surprise, coming only a month after confident boasts of new missions and increased risk that were all working out in Kepler’s favour.

Scarcely a whiff of trouble

“The spacecraft has operated beautifully, with scarcely a whiff of trouble,” said Charlie Sobeck , Kepler and K2 mission manager, noting how NASA had “taken on a bit more risk” to get better shots of planets immense distances from Earth.

Almost 75m miles from Earth, getting information to and from Kepler is a slow process, with 13 minutes the time it takes to send data in one direction.

At the time, Kepler pointing its antenna to Earth, sending information and largely resting up before its latest K2 mission meant it needed to shift around to point directly at the centre of our Milky Way.

However, before it could even turn around, EM was initiated on board, to the surprise of engineers back home. So, turning around wasn’t the cause of the problem, with NASA experts still trying to get to the bottom of what was Kepler’s first EM in seven years.

But major concerns are now over, with regular duties underway.

Microlensing next on the list

Once data is on the ground, the team will thoroughly assess all onboard systems to ensure the spacecraft is healthy enough to return to science mode and begin the K2 mission’s ‘microlensing’ observing campaign, called Campaign 9. This checkout is anticipated to continue through the week.

The outer regions of planetary systems are K2’s new target, with peripheral bodies expected to pour in through Kepler’s lens from hear on out. To do this, a technique called gravitational microlensing is utilised.

For this experiment, astronomers rely on the effect of a familiar fundamental force of nature to help detect the presence of these faraway worlds: gravity. The gravity of massive objects such as stars and planets produces a noticeable effect on other nearby objects.

Earth 2.0

Kepler is a bit of a gem. Completing its primary mission as far back as 2012 and finding 5,000 exoplanets (one-fifth of which have been confirmed) since it began its K2 mission in 2014.

If Kepler gently rings a bell in the recesses of your memory, it might be to do with Earth 2.0, the planet found last summer that is the closest to Earth in terms of orbit, heat, size and potential habitability.

Earth 2.0 (Kepler-452b) is in a solar system very similar to our own and is the right distance from its star to potentially be habitable. The planet is 6bn years old, 60pc larger than Earth and receives 10pc more energy from its star, which is 1.5bn years older and 20pc brighter than our sun, though has the same temperature.

Last month, Kepler captured the moment a star exploded, spotting the resulting shockwave (below) – this was an incredible first. It has even been used to discount alien conspiracies about megastructures on distant stars.